The present invention generally relates to tape recorders in which a tape is movable in two directions during a recording mode thereof, and more particularly to a tape recorder which is designed so that an operation of erroneously setting the tape recorder to the recording mode is prevented, in relation to a tape moving mode which is set and in relation to the existence of forward and reverse erroneous erasure preventing tabs of a loaded tape cassette.
In a general tape recorder of a first type in which only one side of a loaded tape cassette is playable unless the side of the tape cassette is reversed, the tape only moves in a forward direction during a recording mode. Thus, the operation to set the tape recorder to the recording mode is permitted or is prevented, by detecting the existence of a forward erroneous erasure preventing tab of the tape cassette. The operation of setting the tape recorder to the recording mode is prevented when the forward erroneous erasure preventing tab exists.
On the other hand, there is a tape recorder of a second type in which both sides of the loaded tape cassette are playable without reversing the side of the tape cassette. In this tape recorder, the tape moving direction is changed when an end of the tape is reached. In other words, the tape can move in the forward direction or in the reverse direction during the recording mode. Hence, the operation of setting this tape recorder to the recording mode is permitted or is prevented, by detecting the tape moving direction which is set and by detecting the existence of the forward or reverse erroneous erasure preventing tab which corresponds to the set tape moving direction.
A conventional erroneous recording preventing mechanism for preventing the operation of erroneously setting the tape recorder of the second type to the recording mode when the tape recorder should not assume the recording mode, is designed to detect the existence of the forward and reverse erroneous erasure prenenting tabs by a pair of tab detecting members. The tab detecting members are displaced responsive to the existence of the respective forward and reverse erroneous erasure preventing tabs. The displacements of the tab detecting members are transmitted through a plurality of transmitting members which are coupled to the tab detecting members, and a recording button is locked and is prevented from being pushed through the transmitting members. Hence, the conventional erroneous recording preventing mechanism requires a large number of parts, and the construction of the mechanism is complex. On the other hand, there is another erroneous recording preventing mechanism which employs switches. The switches are operated responsive to the displacements of the tab detecting members, and electrical signals from the switches are supplied to an electrical circuit. The pushing of the recording button is permitted or is prevented by a plunger which is activated responsive to an output signal of the electrical circuit. However, the manufacturing cost of this other erroneous recording preventing mechanism is high because of the use of the switch or the like.